Formatted question description: https://leetcode.ca/all/1732.html

1732. Find the Highest Altitude

Level

Easy

Description

There is a biker going on a road trip. The road trip consists of n + 1 points at different altitudes. The biker starts his trip on point 0 with altitude equal 0.

You are given an integer array gain of length n where gain[i] is the net gain in altitude between points i and i + 1 for all (0 <= i < n). Return the highest altitude of a point.

Example 1:

Input: gain = [-5,1,5,0,-7]

Output: 1

Explanation: The altitudes are [0,-5,-4,1,1,-6]. The highest is 1.

Example 2:

Input: gain = [-4,-3,-2,-1,4,3,2]

Output: 0

Explanation: The altitudes are [0,-4,-7,-9,-10,-6,-3,-1]. The highest is 0.

Constraints:

  • n == gain.length
  • 1 <= n <= 100
  • -100 <= gain[i] <= 100

Solution

Start from altitude 0 and calculate altitudes at all indices. Maintain the highest altitude during the process. Finally, return the highest altitude.

  • class Solution {
        public int largestAltitude(int[] gain) {
            int maxAltitude = 0;
            int altitude = 0;
            int length = gain.length;
            for (int i = 0; i < length; i++) {
                altitude += gain[i];
                maxAltitude = Math.max(maxAltitude, altitude);
            }
            return maxAltitude;
        }
    }
    
  • // OJ: https://leetcode.com/problems/find-the-highest-altitude/
    // Time: O(N)
    // Space: O(1)
    class Solution {
    public:
        int largestAltitude(vector<int>& A) {
            int h = 0, ans = 0;
            for (int n : A) ans = max(ans, h += n);
            return ans;
        }
    };
    
  • # 1732. Find the Highest Altitude
    # https://leetcode.com/problems/find-the-highest-altitude/
    
    class Solution:
        def largestAltitude(self, gain: List[int]):
            res = [0]
            for g in gain:
                res.append(res[-1] + g)
            
            return max(res)
            
    

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